Aspirin

I was curious about aspirin. I know it does wonders on my headaches, but how? and why? Approximately 8 billion Aspirin tablets are taken per year for a variety of reasons including:

• Inflammation
• headaches
• pain
• fever
• preventing heart attacks
• arthritis

As far back as the fifth century B.C. a bitter powder made from willow tree bark has been used to ease aches and pains. The first person to write about this was Hippocrates. In the 1700's Reverend Edmond Stone noticed the abilities of willow to cure fevers with aches, and he wrote about it. Early scientists only knew that the willow bark was bitter and good for fever and pain because of a chemical called salicin (discovered in 1829). (picture of the willow to the left)

Salicin is an acid that is very rough on the stomach lining causes a great deal of problems. As a result a chemist Felix Hoffmann who worked for the company Fredrich Bayer & Co. tested compounds to fix the problem. The result was acetylsalicylic acid (ASA or aspirin) it was gentler than salicin to the stomach and more effective against pain, swelling and fever. It was then named after a rose that actually produces the compound naturally (picture to the left).

ASA is made of 8 Hydrogen (white), 9 Carbon (green), and 4 Oxygen (red). The chemical formula is C9H8O4, and it is a complex made up of acetic acid and salicylic acid.

In the early 1970's it was finally discovered how aspirin works, in 1982 John Vane and his colleges were awarded the Nobel Prize in Medicine for showing how aspirin works.

Here is a very simplified explanation of how aspirin works:

Your body produces a enzyme called cyclooxygenase 2 (COX-2). When in pain COX-2 changes into a chemical called prostaglandins which increases the strength of the signal being transmitted to your brain. Aspirin attaches itself to COX-2 and prevents it from turning into prostaglandins which is what causes it to appear to be relieving the pain. Aspirin only works for 4-6 hours because that's how long it takes your body to process it out of your system.

To the right you have a picture of a man trying to build a model of the complex COX-2 molecule. Below you have a diagram of prostaglandins.

Why there are so many warnings about not taking excessive aspirin:

COX-2 is all over your body and doesn't just turn into prostaglandins when your in pain. In your stomach, it is produced constantly so that your body keeps up with the rebuilding of the stomach lining, this keeps the lining thick which is what protects the rest of your body from your stomach acid. To add insult to injury, Aspirin is an acid, so along with weakening your stomach lining over time, it can also cause your stomach lining to break down leading to some serious stomach problems. Prostaglandins aids with blood clotting, so by preventing it from being made, blood clotting slows down It can prevent heart attacks, but can als cause serious injuries to bleed longer.

Aspirin is one of the oldest known drugs, and it was one of the first drugs to be artificially produced on a large scale by the pharmaceutical industry. Like any drug, aspirin can be dangerous when taken in excess or when not following the directions. However, it is a very widely used drug that is beneficial to the millions of people who take it every day.